1. Field of the Invention
The present invention pertains to a device for fastening a vibrating wire and, more particularly, to a device for fastening a vibrating wire to a component of a measuring device or meter such as a dynamometer, for example.
2. History of the Prior Art
Measuring devices or meters which use vibrating wires for a frequency transmitter are described in Swiss Patent No. 447,653, for instance. The frequency of such wires is determined not only by their mass, length and tension, but also by the type of fastener with which they are attached to other components of the measuring device. Moreover, the wires must be electrically insulated from the energy transmission chain at one end at least.
German Patent No. 2,239,997 describes a fastening device which meets most of the claims for the mechanism fastening wire to other components of a meter. In particular, the two ends of the wire form nodes of oscillation, and the wire is attached to the connectors in such a way that virtually no energy of oscillation is lost in friction. If the wire must also be electrically insulated, this is accomplished by means of an insulated screw connection, which electrically insulates the connector parts from the other components of the meter or measuring device. However, when the connection must be absolutely reliable, this type of connection becomes very costly.
The purpose of the invention is to provide a more economical way of dependably insulating the wire electrically from the other components of the measuring device or meter without sacrificing the advantages of this fastening mechanism. These advantages include formation of a node of oscillation at the point of fastening, the ability of the fastening device to function as a stop band filter between the wire and the energy transmission chain, and the elimination of energy loss in mechanical friction.
The present invention overcomes the problems of the prior art with a fastening device consisting of a body with two prongs and two retainers made of an insulating material in which the retainers contact the prongs on one side and, due to the clamping action of the prongs, hold the full width of the wire by friction on the other side, insulating it electrically.